package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import org.apache.tomcat.util.http.fileupload.IOUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file file要和前台的上传文件名字一致
     * @return
     * @throws IOException
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) throws IOException {
        //    1.判断basePath是否存在
        File dir = new File(basePath);
        if (!dir.exists()) {
            dir.mkdirs();//创建文件目录
        }
        //    2.生成UUID唯一文件名
        String substring = file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf("."));//抽取后缀名
        String filename = UUID.randomUUID().toString() + substring;
        //    3.将临时文件持久化到指定目录
        file.transferTo(new File(basePath + filename));
        return R.success(filename);
    }

    /**
     * 文件下载
     *
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws Exception {
        //    将服务器文件以流的形式响应
        //    1.输入流：读文件
        FileInputStream fis = new FileInputStream(basePath + name);
        //    2.输出流，response响应文件到前台
        ServletOutputStream os = response.getOutputStream();
        //    3.输入流和输出流对接
        IOUtils.copy(fis, os);
        fis.close();
    }
}
